Endless Track And Guide Member

ABSTRACT

A track assembly is formed from an endless track, an elongate guide member, a drive sprocket, and a plurality of track engaging rollers. The endless track has an inner surface having a plurality of parallel circumferential ridges. Formed between the circumferential ridges is a circumferential channel. The guide member is at least partially positioned and closely received within the circumferential channel. The track engaging rollers are arranged in a pair of parallel rows near an outer side of each circumferential ridge. During track rotation, the guide member remains closely received within the channel, and the rollers contact the outer side of the ridges to resist lateral movement of the track. Positioning of the guide member in the circumferential channel, with the rollers outside the ridges, laterally stabilizes the track thereby reducing the risk of the track slipping off the track assembly.

FIELD

The present invention relates to track assemblies and more particularlyto endless tracks and guide members for such track assemblies.

SUMMARY

The invention is directed to a flexible, endless track having an innersurface. Formed on the inner surface are a plurality of circumferentialridges. The circumferential ridges are situated in parallel relationshipsuch that a circumferential channel is formed between an adjacent pairof the ridges.

A track assembly is formed from the endless track, a rotatable drivesprocket, and an elongate guide member. The endless track is supportedon the drive sprocket, and the guide member is at least partiallysituated within the channel of the endless track.

A tracked vehicle is formed from a plurality of the track assemblies, achassis, and an engine supported by the chassis. The track assembliesare configured to support the chassis while engaging the ground.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side elevation view of a track assembly.

FIG. 2 is a perspective view of an endless track of the track assemblyof FIG. 1.

FIG. 3 is a perspective view of a guide member of the track assembly ofFIG. 1.

FIG. 4 is a side elevation view of the guide member of FIG. 3.

FIG. 5 is a side elevation view of a partial track assembly, showing thetrack assembly of FIG. 1 with the endless track removed.

FIG. 6 is a perspective view of the assembly of FIG. 5.

FIG. 7 is a bottom plan view of the assembly of FIG. 5.

FIG. 8 is an end elevation view of the assembly of FIG. 5, showing aplane traversing a drive sprocket and the guide member.

FIG. 9 is a cross-sectional perspective view of the track assembly ofFIG. 1, taken along line 9-9, and showing the guide member positioned ina channel of the endless track.

FIG. 10 is another cross-sectional perspective view of the trackassembly of FIG. 1, taken along line 9-9, and showing the guide memberpositioned in the channel.

FIG. 11 is a side elevation view of a first side of another embodimentof a track assembly.

FIG. 12 is a perspective view of the first side of the track assembly ofFIG. 11.

FIG. 13 is a side elevation view of a second side of the track assemblyof FIG. 11.

FIG. 14 is a perspective view of the second side of the track assemblyof FIG. 11.

FIG. 15 is a side elevation view of a partial track assembly, showingthe track assembly of FIG. 11 with the track removed.

FIG. 16 is a perspective view of the partial track assembly of FIG. 15.

FIG. 17 is a cross-sectional view of the track assembly of FIG. 11,taken along line 17-17, and showing a frame having a guide memberpositioned in a channel of an endless track.

FIG. 18 is a vehicle having a chassis supported by a plurality of thetrack assemblies of FIG. 1.

FIG. 19 is a vehicle having a chassis supported by a plurality of thetrack assemblies of FIG. 11.

DETAILED DESCRIPTION

Tracked vehicles are often used to travel across difficult surfaceconditions such as mud, sand, snow, rugged terrain, or unstable ground.In such conditions, tracked vehicles are advantageous because trackstend to spread the weight of the vehicle out across a broad surfacearea. Spreading the weight of the vehicle out using tracks increasestraction while decreasing the likelihood that ruts or other surfacedamage will occur. For these reasons tracked vehicles have been popularin the agricultural and construction industries where large vehiclesweighing several thousand pounds are often used. However, operatingheavy vehicles on uneven terrain may cause the track assemblies to betilted such that the endless tracks slip off the track assemblies. Thusit is desirable to provide tools and methods for maintaining the lateralposition of the track on the track assembly.

Said tracked vehicles have several configurations and uses. For example,as shown in FIG. 19, a standard skid-steer vehicle having two trackassemblies is shown. While the track assemblies shown in FIG. 19 aregenerally triangular, these may also be configured as an oval. Suchtwo-track configurations “skid-steer” by changing the relative velocityof each track—turning left, for example, by rotating the left trackforward faster than the right track is rotated. As shown in FIG. 18,four track frames may alternatively be used. Such a configuration may“skid-steer”, or may have a steerable axle. Additionally, track framesmay be utilized in conjunction with other ground engaging members, suchas wheels. In any case, the type of vehicle and the number orconfiguration of track frames is not limiting on the invention. Thepresent invention may be utilized with any such track frame.

With reference to FIG. 18, a tracked vehicle 10 for driving overdifficult terrain conditions is shown. The tracked vehicle 10 comprisesa chassis 12, an engine (not shown) that is supported on the chassis 12,an operator station 14, and a plurality of track assemblies 16. Thechassis 12 may support a work tool 18, such as a backfill blade, orattachments such as a trencher, plow, or earth saw. The track assemblies16 engage the ground and support the chassis 12. With reference to FIG.1, each track assembly 16 comprises a frame 20, a drive sprocket 22, aguide member 24, a plurality of track-engaging rollers 74, 76, 78, aplurality of track tensioning assemblies 28, and an endless track 30.

In FIG. 18, the tracked vehicle 10 is supported on a plurality of thetrack assemblies 16 of FIG. 1. The vehicle 10 preferably has four trackassemblies 16 that function similarly to traditional wheels. An operatorcontrols the power from the engine to rotate the drive axles and theconnected drive sprockets 22 and tracks 30. Moving the tracks 30 in afirst direction causes the vehicle 10 to drive forward, and moving thetracks 30 in a second direction causes the vehicle 10 to drive inreverse. Each track assembly 16 may pivot about a vertical steering axisto allow the operator to change direction of the vehicle 10 as ittravels over the ground. The vehicle 10 may be steered by the operatorusing the steering wheel to turn the track assemblies 16 at the front ofthe vehicle 10. In another embodiment, the vehicle 10 may be equippedwith four-track steering such that operation of the steering wheelcauses all four track assemblies 16 to pivot about their respective axesto turn the vehicle 10. When turning or operating the vehicle 10 onuneven surfaces, lateral forces may be applied to the track assemblies16.

Shown in FIG. 19 is another embodiment of a tracked vehicle 158. Thetracked vehicle 158 is supported on a plurality of track assemblies 102of FIG. 11. Much as in the embodiment of FIG. 1, the tracked vehicle 158comprises a chassis 160, an engine (not shown) that is supported on thechassis, an operator station 162, and the plurality of track assemblies102. However, the tracked vehicle 158 has two track assemblies 102,rather than four. While the track assemblies 10, 158 shown in FIGS. 18and 19 are generally triangular in shape, the track assemblies may haveany suitable shape, including an oblong shape.

Turning to FIGS. 1 and 5-10, the frame 20 is formed from a strong anddurable material such as steel. The frame 20 has an outboard sideassembly 32 and an inboard side assembly 34. Each side assembly 32, 34has a pair of spaced apart outer and inner plates 36, 38 arranged inparallel relationship. Preferably, the inner plate 38 of the outboardside assembly 32 is arranged in parallel relationship to the inner plate38 of the inboard side assembly 34. The outer and inner plates 36, 38are attached by a plurality of connectors 40 which may comprise struts.Likewise, the outer and inner side assemblies 32, 34 are attached toeach other by a plurality of connectors 42, such as struts. On the lowerside of the track assembly 16, a plurality of cross braces 44 extendbetween the side assemblies 32, 34.

The drive sprocket 22 is formed from a strong and durable material suchas steel. Preferably, the drive sprocket 22 has the shape of a dischaving a plurality of projections 46 extending radially outward. Asshown in FIG. 5, the drive sprocket 22 comprises a plurality of curvedsections 48 connected together by a plurality of connectors 50. Thedrive sprocket 22 may have a central track hub 52 which connects to ahub assembly 54. The hub assembly 54 transfers torque to the drivesprocket from a drive axle (not shown). Mounted on the hub assembly 54,the drive sprocket 22 is rotatable relative to the frame 20. As shown inFIGS. 6 and 8, the drive sprocket 22 is positioned between the outboardside assembly 32 and the inboard side assembly 34. The hub assembly 54is at least partially situated within a concavity 56 formed in theoutboard side assembly 32. In the embodiment of FIGS. 1-10, the drivesprocket 22 is generally centered between the longitudinal extremitiesof the frame 20.

Shown in FIGS. 3 and 4 is the guide member 24 of the track assembly 16of FIG. 1. The guide member 24 is formed from a strong and durablematerial, such as steel. The guide member 24 is characterized by anelongate shape and has an upper surface 58, a lower surface 60, andopposed first and second ends 62, 64. In each end 62, 64, a notch 66 isformed. The upper surface 58 is characterized by a concavity 68 formedbetween the notches 66. The lower surface 60 has an upwardly curvedportion 70 on each end 62, 64.

As shown in FIGS. 6 and 7, the guide member 24 is supported by theplurality of cross braces 44 which are supported on the frame 20. Thecross braces 44 extend transversely within the notches 66 formed in theguide member 24. The guide member 24 may be attached to the cross braces44 by using a plurality of connectors, such as bolts, or by a fusionprocess, such as welding.

As shown in FIG. 8, the guide member 24 may be situated beneath thedrive sprocket 22 such that a single plane 72 longitudinally traversesboth the drive sprocket 22 and the guide member 24. As best shown inFIGS. 6 and 9, the guide member 24 should be positioned such that atleast a peripheral portion of the drive sprocket 22 resides within theconcavity 68. Preferably, the shape of the concavity 68 conforms to theprofile of the resident portion of the drive sprocket 22.

Shown in FIGS. 1 and 5-7, the plurality of rollers comprise a first endroller 74, a second end roller 76, and a plurality of bogie rollers 78situated between the first and second end rollers 74,76. The rollers 74,76, 78 are formed from a strong and durable material, such as steel. Anaxle 80 of the first end roller 74 is disposed within a slot 82 formedin the inner plate 38 of the side assemblies 32, 34. Positioning theaxle 80 within the slot 82 allows the first end roller 74 to moverelative to the frame 20 so that the track tension can be adjusted. Therollers 74, 76, 78 are supported on each of the side assemblies 32, 34and are arranged in a pair of rows in parallel relationship. As shown inFIGS. 6 and 7, the guide member 24 is situated between the parallel rowsof rollers 74, 76, 78.

A pair of the track tensioning assemblies 28 are supported on each sideassembly 32, 34 of the frame 20. Each track tensioning assembly 28 maycomprise a pivot arm or a linear actuator, such as a grease cylinder, ahydraulic cylinder, a pneumatic cylinder, or a jackscrew. As shown inFIGS. 5-7, each track tensioning assembly 28 comprises a jackscrew 84having opposed first and second ends 86, 88. The first end 86 isattached to the axle 80 of the first end roller 74, and the second end88 is attached to the frame 20. By extending or retracting the jackscrew84, the distance between the first end roller 74 and the frame 20 isincreased or decreased respectively. Increasing the distance adjusts thetension of the endless track 30 so that it fits more tightly around thedrive sprocket 22 and rollers 74, 76, 78.

Referring to FIG. 2, the endless track 30 is formed from a strong,durable, and flexible material, such as rubber. The track 30 forms acontinuous loop surrounding an interior area 90. The track 30 has aninner surface 92 that bounds the interior area 90 and an outer surface94 that contacts the ground. To provide improved traction, the outersurface 94 may be treaded. The treads may be characterized by a patternof grooves 96 formed in at least a portion of the area where the trackmakes surface contact. Formed on the inner surface 92 are a plurality ofcircumferential ridges 98 in parallel relationship. A circumferentialchannel 100 is formed between an adjacent pair of circumferential ridges98 and opens toward the interior area 90.

An assembled track assembly 16 is shown in FIGS. 1, 9, and 10. The track30 is stretched around the drive sprocket 22 and the rollers 74, 76, 78.By using the pair of tensioning assemblies 28 to increase or decreasethe distance between each first end roller 74 and the frame 20, thetension within the track 30 is adjusted. The track 30 is positioned suchthat the drive sprocket 22 and the rollers 74, 76, 78 contact the innersurface 92 of the track 30. As the drive sprocket 22 is rotated, theprojections 46 of the drive sprocket 22 engage the inner surface 92 ofthe track 30 at the upper portion of its circuit causing the track 30 totravel around the drive sprocket 22 and rollers 74, 76, 78.

With reference to FIGS. 1-4, 9, and 10, the drive sprocket 22 and theguide member 24 are each partially situated within the channel 100 ofthe track 30. The guide member 24 has a width that closely fits withinthe channel 100. As the track 30 moves around its circuit, it passeseach end 62, 64 of the guide member 24 while engaging the ground.Because the ends 62, 64 of the guide member 24 curve upwardly, frictionbetween the guide member 24 and track 30 is minimized. As the track 30moves, the guide member 24 remains positioned within the track'sinternal channel 100, thus biasing the track 30 against lateral movementthat might result in its slipping off the rollers 74, 76, 78. Anylateral movement of the track assemblies 16 is further deflected by therollers 74, 76, 78 that are positioned near the ridges 98 forming thechannel 100 that surrounds the guide member 24.

FIGS. 11-17 and 19 show another embodiment of the track assembly 102having an endless track 104 and a guide member 106. The track assembly102 comprises a frame 108, a drive sprocket 110, a plurality oftrack-engaging rollers 112, 114, 116, a track tensioning assembly 118,and the endless track 104. Rather than having a separate guide member,the guide member 106 is incorporated into the frame 108 in thisembodiment. Referring to FIGS. 15 and 16, the frame 108 has an elongatebody 120 having opposed first and second ends 122, 124, a first side126, a second side 128, an upper surface 130, and a lower surface 132.As best shown in FIG. 15, the lower surface 132 curves upwardly at thefirst and second ends 122, 124. Situated near the second end 124 of theframe 108, the drive sprocket 110 has a plurality of projections 111.

The plurality of rollers comprise a pair of first end rollers 112, apair of second end rollers 114, and at least one pair of bogie rollers116. Situated on each side of the frame 108, the rollers 112, 114, 116are arranged in a pair of rows in parallel relationship. The pair ofsecond end rollers 112 are mounted on an axle 134 near the second end124 of the frame 108. The track tensioning assembly 118 comprises ajackscrew 136 having a first end attached to the axle 134 and a secondend attached to the frame 108. Extending the jackscrew 136 tightens thetension within the track 104.

As shown in FIGS. 11, 13, 15, and 16, a locking assembly 142 may besupported on the frame 108 of each track assembly 102. The lockingassembly 142 comprises a pair of plates 144 between which the sprocket110 partially extends. The plates 144 are penetrated by one or morepairs of aligned holes 146 situated within the footprint of the sprocket110. A pair of holes 146 in the plates 144 may be aligned with a spaceformed between a pair of adjacent projections 111 of the sprocket 110. Apin 150, preferably having an enlarged head at one end, may be insertedthrough the aligned holes 146 and the space between the projections 111.Thus installed, the pin 150 locks the sprocket 110 against rotation. Anadditional pair of aligned storage holes 152 in the plate 144 may beused for storage of the pin 150 when the sprocket 110 is unlocked. Thesestorage holes 152 are positioned outside the footprint of the sprocket110.

The assembled track assembly 102 is shown in FIGS. 11-14 and 17. Much aswith the embodiment of FIGS. 1-10, the track 104 extends around thesprocket 110 and the rollers 112, 114, 116. The track 104 has aplurality of circumferential ridges 154 formed in an inner surface 155of the track. A circumferential channel 156 is formed between anadjacent pair of the ridges 154. The rollers 112, 114, 116 arepositioned near the ridges 154. As in the embodiment of FIGS. 1-10, theguide member 106 extends into the circumferential channel 156 tolaterally stabilize the track 104. However, the guide member 106 is nota separate piece from the frame 108 in the embodiment of FIGS. 11-17.

Changes may be made in the construction, operation and arrangement ofthe various parts, elements, steps and procedures described hereinwithout departing from the spirit and scope of the invention asdescribed in the following claims.

1. A track assembly, comprising: a flexible, endless track having aninner surface having a plurality of circumferential ridges in parallelrelationship in which a circumferential channel is formed between anadjacent pair of circumferential ridges; a rotatable drive sprocket, inwhich the endless track is supported on the drive sprocket; a frame thatextends at least partially within the channel of the endless track; anda plurality of track engaging rollers supported by the frame.
 2. Thetrack assembly of claim 1 in which the frame is a single piece.
 3. Thetrack assembly of claim 1 in which the plurality of track engagingrollers are uniformly spaced on the frame.
 4. The track assembly ofclaim 1 further comprising a locking assembly supported by the frame,and comprising: a pair of plates between which the drive sprocketpartially extends.
 5. The track assembly of claim 4 in which the lockingassembly has one or more pairs of aligned holes situated within afootprint of the drive sprocket.
 6. The track assembly of claim 5 inwhich the locking assembly further comprises: a pin configured to bereceived within one of the pairs of aligned holes.
 7. The track assemblyof claim 4 in which the locking assembly is positioned between the drivesprocket and the frame.
 8. The track assembly of claim 1 in which therotational axis of the drive sprocket is spaced above the upper surfaceof the frame.
 9. The track assembly of claim 1 in which at least onenotch is formed in one of the plurality of circumferential ridges.
 10. Avehicle, comprising: a chassis; an engine supported by the chassis; anda pair of the track assemblies of claim 1 disposed in ground-engagingrelationship and supporting the chassis.
 11. The track assembly of claim1 in which the endless track is formed of rubber.
 12. The track assemblyof claim 1 in which the footprints of the frame and the drive sprocketoverlap.
 13. The track assembly of claim 1 in which at least one planetraverses both the drive sprocket and the frame.
 14. The track assemblyof claim 1 in which the frame has a curved lower surface adjacent eachend.
 15. The track assembly of claim 1 in which the endless tracksurrounds an interior and in which the channel opens toward thatinterior.
 16. The track assembly of claim 1 further comprising ajackscrew attached to the frame and at least one of the plurality oftrack engaging rollers.
 17. The track assembly of claim 1 in which theplurality of track engaging rollers are identically sized.
 18. The trackassembly of claim 1 in which the plurality of track engaging rollers arearranged in a pair of parallel rows and in which the frame is situatedbetween the rows.
 19. The track assembly of claim 18 in which therotational axes of the plurality of rollers are coplanar.
 20. The trackassembly of claim 1 in which each of the plurality of track engagingrollers has a maximum diameter that is greater than the height of theframe.
 21. The track assembly of claim 10 in which the frame issupported by the chassis.
 22. The track assembly of claim 1 in which theplurality of track engaging rollers comprises a pair of first endrollers, a pair of second end rollers and one and only one pair of bogierollers positioned between the first and second end rollers.
 23. Thetrack assembly of claim 1 in which the plurality of track engagingrollers comprises three and only three pairs of rollers.
 24. The trackassembly of claim 1 in which the plurality of circumferential ridges areof uniform height.
 25. The track assembly of claim 1 in which theplurality of track engaging rollers comprises a pair of first endrollers and an opposed pair of second end rollers, and in which theentire lowermost edge of the frame between the first and second endrollers is at least partially positioned within the channel.